The U.S. electric grid is in need of significant and rapid transmission expansion to meet growing power demand, ensure resilience and reliability, and enable lowest cost electricity generation. The U.S. Department of Energy released The National Transmission Needs Study at the end of 2023, finding a median need for 57% growth in transmission infrastructure by 2035 compared to today’s system through a review of transmission studies and scenarios. New high-voltage transmission will be key to interconnecting more renewable energy to address climate change, as summer 2023 broke heat records again. The Net-Zero America Study at Princeton found that 80% of the potential greenhouse gas emissions reductions delivered by the Inflation Reduction Act (IRA) will be lost without doubling the current rate of transmission expansion.

While the need for more transmission capacity is clear, utilities are not responding. Construction of new high-voltage transmission has slowed to a trickle over the past decade. Despite this decline in new construction, annual transmission spend has hit an all-time high — over $25 billion per year — with 90% of this spend driven by reliability upgrades and the replacement of aging equipment.

The federal government has taken steps to incentivize the construction of new lines — the Federal Energy Regulatory Commission (FERC) published Order No. 1920 in May 2024 to transform regional transmission planning practices, and the U.S. Department of Energy (DOE) has taken action by issuing new rules to support siting, permitting, and funding for new lines. Section 3 describes these programs. However, a significant increase in federal funding and utility investment in new greenfield high-capacity projects is still needed to truly move the needle on transmission expansion and ensure a reliable and affordable transition to a cleaner grid. While new transmission is being built, utilities can fully avail themselves of Advanced Transmission Technologies (ATTs) such as reconductoring and Grid Enhancing Technologies (GETs) to upgrade existing transmission lines, congruent with the White House goal announced in April 2024 to “upgrade 100,000 miles of transmission lines over the next five years.”